Ancient medical practitioners believed that a healthy body had a balance of
four essential fluids, also known as humors (from Latin humere: to be wet,
which also gave us the word humid). Those humors were blood, yellow bile
(aka choler), black bile, and phlegm. Each humor was associated with a season
and an element (air, water, fire, and earth). An imbalance of humors was
thought to cause a change in temperament or worse.

Thankfully, we have come a long way from that theory about the human body.
We no longer use that method to diagnose people's conditions, though the
terms live on in the language by being used as metaphors.

choleric

PRONUNCIATION:

(KAHL-uhr-ik)

MEANING:

adjective:
Easily irritated or angered; hot-tempered.

ETYMOLOGY:

From Latin cholericus, from Greek cholerikos, from chole (bile). Ultimately
from the Indo-European root ghel- (to shine) that is also the source of words
such as yellow, gold, glimmer, gloaming, glimpse, glass, arsenic, and cholera.

USAGE:

"In every choleric outburst from Sir Alan, every lifted eyebrow and pursed
lip from his lieutenants, the subtext is clear."
Libby Purves; The Apprentice; The Daily Telegraph (London, UK); Jun 6, 2009.